In C3-type plants, like wheat, soybeans, and rice, the enzyme Rubisco fixes carbon dioxide from the atmosphere into sugar during photosynthesis, but about 35 percent of the time Rubisco binds oxygen instead of carbon dioxide producing a plant-toxic carbon compound called glycolate. The plant makes the best of a bad situation by salvaging a portion of the carbon in glycolate by creating a compound that can be used in photosynthesis through a complex network of enzyme reactions in multiple organelles. This process, called photorespiration, recovers 75 percent of the carbon—but the plant expends a large amount of in this recovery process. Some bacteria have simpler pathways that require less energy. For this objective, RIPE is replacing the native pathway with these more efficient bacterial pathways and other novel synthetic pathways in order to make photosynthesis more efficient. This work has resulted in a 40 percent increase in crop productivity and was published in Science in 2019. Learn more in the video and articles below.
The RIPE project has engineered a shortcut for photorespiration—an energy-expensive process—and increased crop productivity by 40 percent.
Instead of turning carbon into food, many plants accidentally make a plant-toxic compound during photosynthesis that is recycled through a process called photorespiration. University of Illinois and USDA/ ARS researchers report in Plant Cell the discovery of a key protein in this process, which they hope to manipulate to increase plant productivity.